package cn.sumpu.toolkit.image;

import java.awt.Graphics;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Transparency;
import java.awt.image.BufferedImage;  
import java.awt.image.ColorModel;
import java.awt.image.PixelGrabber;
import java.io.ByteArrayOutputStream;
import javax.imageio.ImageIO;  
import javax.swing.ImageIcon;
public class ScaleImage {
	 	private static int width;  
	  
	    private static int height;  
	  
	    private static int scaleWidth;  
	  
	    static  double support = (double) 3.0;  
	  
	    static  double PI = (double) 3.14159265358978;  
	  
	    static double[] contrib;  
	  
	    static double[] normContrib;  
	  
	    static double[] tmpContrib;  
	  
	    static int startContrib, stopContrib;  
	  
	    static int nDots;  
	  
	    static int nHalfDots;  
	  
	    /**  
	     * Start: Use Lanczos filter to replace the original algorithm for image 
	     * scaling. Lanczos improves quality of the scaled image modify by :blade 
	     */  
	  
	    public static void main(String[] args) {  
	        //ScaleImage is = new ScaleImage();  
	        try {  
	        	BufferedImage srcImage=new BufferedImage(200, 1, 0);
	        	//saveImageAsJpg(srcImage, "C:/temp/xianpian_153.jpg", 153,  112);  
	            System.out.println("success");  
	        } catch (Exception e) {
	            // TODO Auto-generated catch block  
	            e.printStackTrace();  
	        }  
	    }  
	     
	    /** 
	     *  
	     * @param fromFileStr 原图片地址 
	     * @param saveToFileStr  生成缩略图地址 
	     * @param formatWideth  生成图片宽度 
	     * @param formatHeight 生成图片高度 
	     */  
	    public static byte[] saveImageAsJpg(BufferedImage srcImage, int formatWideth, int formatHeight) throws Exception {  
	    	int imageWideth = srcImage.getWidth(null);  
	        int imageHeight = srcImage.getHeight(null);  
	        int changeToWideth = 0;  
	        int changeToHeight = 0;  
	        if (imageWideth > 0 && imageHeight > 0) {  
	            if (imageWideth / imageHeight >= formatWideth / formatHeight) {
	                if (imageWideth > formatWideth) {  
	                    changeToWideth = formatWideth;  
	                    changeToHeight = (imageHeight * formatWideth) / imageWideth;  
	                } else {  
	                    changeToWideth = imageWideth;  
	                    changeToHeight = imageHeight;  
	                }  
	            } else {  
	                if (imageHeight > formatHeight) {  
	                    changeToHeight = formatHeight;  
	                    changeToWideth = (imageWideth * formatHeight) / imageHeight;  
	                } else {  
	                    changeToWideth = imageWideth;  
	                    changeToHeight = imageHeight;  
	                }  
	            }  
	        }  
	  
	        srcImage = imageZoomOut(srcImage, changeToWideth, changeToHeight);  
	        ByteArrayOutputStream bao_org = new ByteArrayOutputStream();
	        ImageIO.write(srcImage, "JPEG", bao_org);  
	        return bao_org.toByteArray();
	    }  
	  
	    public static BufferedImage imageZoomOut(BufferedImage srcBufferImage, int w, int h) {
	        width = srcBufferImage.getWidth();  
	        height = srcBufferImage.getHeight();  
	        scaleWidth = w;  
	  
	        if (DetermineResultSize(w, h) == 1) {
	            return srcBufferImage;  
	        }  
	        calContrib();  
	        BufferedImage pbOut = HorizontalFiltering(srcBufferImage, w);  
	        BufferedImage pbFinalOut = verticalFiltering(pbOut, h);  
	        return pbFinalOut;  
	    }  
	  
	    /**  
	     * 决定图像尺寸 
	     */  
	    private static int DetermineResultSize(int w, int h) {
	        double scaleH, scaleV;  
	        scaleH = (double) w / (double) width;  
	        scaleV = (double) h / (double) height;  
	        // 需要判断一下scaleH，scaleV，不做放大操作  
	        if (scaleH >= 1.0 && scaleV >= 1.0) {  
	            return 1;  
	        }  
	        return 0;  
	  
	    } // end of DetermineResultSize()  
	  
	    private static double Lanczos(int i, int inWidth, int outWidth, double Support) {  
	        double x;  
	  
	        x = (double) i * (double) outWidth / (double) inWidth;  
	  
	        return Math.sin(x * PI) / (x * PI) * Math.sin(x * PI / Support)  
	                / (x * PI / Support);  
	  
	    }  
	  
	    private static void calContrib() {  
	        nHalfDots = (int) ((double) width * support / (double) scaleWidth);  
	        nDots = nHalfDots * 2 + 1;  
	        try {  
	            contrib = new double[nDots];  
	            normContrib = new double[nDots];  
	            tmpContrib = new double[nDots];  
	        } catch (Exception e) {  
	            System.out.println("init   contrib,normContrib,tmpContrib" + e);  
	        }  
	  
	        int center = nHalfDots;  
	        contrib[center] = 1.0;  
	  
	        double weight = 0.0;  
	        int i = 0;  
	        for (i = 1; i <= center; i++) {  
	            contrib[center + i] = Lanczos(i, width, scaleWidth, support);  
	            weight += contrib[center + i];  
	        }  
	  
	        for (i = center - 1; i >= 0; i--) {  
	            contrib[i] = contrib[center * 2 - i];  
	        }  
	  
	        weight = weight * 2 + 1.0;  
	  
	        for (i = 0; i <= center; i++) {  
	            normContrib[i] = contrib[i] / weight;  
	        }  
	  
	        for (i = center + 1; i < nDots; i++) {  
	            normContrib[i] = normContrib[center * 2 - i];  
	        }  
	    } // end of CalContrib()  
	  
	    // 处理边缘  
	    private static void CalTempContrib(int start, int stop) {  
	        double weight = 0;  
	  
	        int i = 0;  
	        for (i = start; i <= stop; i++) {  
	            weight += contrib[i];  
	        }  
	  
	        for (i = start; i <= stop; i++) {  
	            tmpContrib[i] = contrib[i] / weight;  
	        }  
	  
	    } // end of CalTempContrib()  
	  
	    private static int GetRedValue(int rgbValue) {  
	        int temp = rgbValue & 0x00ff0000;  
	        return temp >> 16;  
	    }  
	  
	    private static int GetGreenValue(int rgbValue) {  
	        int temp = rgbValue & 0x0000ff00;  
	        return temp >> 8;  
	    }  
	  
	    private static int GetBlueValue(int rgbValue) {  
	        return rgbValue & 0x000000ff;  
	    }  
	  
	    private static int ComRGB(int redValue, int greenValue, int blueValue) {  
	  
	        return (redValue << 16) + (greenValue << 8) + blueValue;  
	    }  
	  
	    // 行水平滤波  
	    private static int HorizontalFilter(BufferedImage bufImg, int startX, int stopX,  
	            int start, int stop, int y, double[] pContrib) {  
	        double valueRed = 0.0;  
	        double valueGreen = 0.0;  
	        double valueBlue = 0.0;  
	        int valueRGB = 0;  
	        int i, j;  
	  
	        for (i = startX, j = start; i <= stopX; i++, j++) {  
	            valueRGB = bufImg.getRGB(i, y);  
	  
	            valueRed += GetRedValue(valueRGB) * pContrib[j];  
	            valueGreen += GetGreenValue(valueRGB) * pContrib[j];  
	            valueBlue += GetBlueValue(valueRGB) * pContrib[j];  
	        }  
	  
	        valueRGB = ComRGB(clip((int) valueRed), clip((int) valueGreen),  
	                clip((int) valueBlue));  
	        return valueRGB;  
	  
	    } // end of HorizontalFilter()  
	  
	    // 图片水平滤波  
	    private static BufferedImage HorizontalFiltering(BufferedImage bufImage, int iOutW) {  
	        int dwInW = bufImage.getWidth();  
	        int dwInH = bufImage.getHeight();  
	        int value = 0;  
	        BufferedImage pbOut = new BufferedImage(iOutW, dwInH,  
	                BufferedImage.TYPE_INT_RGB);  
	  
	        for (int x = 0; x < iOutW; x++) {  
	  
	            int startX;  
	            int start;  
	            int X = (int) (((double) x) * ((double) dwInW) / ((double) iOutW) + 0.5);  
	            int y = 0;  
	  
	            startX = X - nHalfDots;  
	            if (startX < 0) {  
	                startX = 0;  
	                start = nHalfDots - X;  
	            } else {  
	                start = 0;  
	            }  
	  
	            int stop;  
	            int stopX = X + nHalfDots;  
	            if (stopX > (dwInW - 1)) {  
	                stopX = dwInW - 1;  
	                stop = nHalfDots + (dwInW - 1 - X);  
	            } else {  
	                stop = nHalfDots * 2;  
	            }  
	  
	            if (start > 0 || stop < nDots - 1) {  
	                CalTempContrib(start, stop);  
	                for (y = 0; y < dwInH; y++) {  
	                    value = HorizontalFilter(bufImage, startX, stopX, start,  
	                            stop, y, tmpContrib);  
	                    pbOut.setRGB(x, y, value);  
	                }  
	            } else {  
	                for (y = 0; y < dwInH; y++) {  
	                    value = HorizontalFilter(bufImage, startX, stopX, start,  
	                            stop, y, normContrib);  
	                    pbOut.setRGB(x, y, value);  
	                }  
	            }  
	        }  
	  
	        return pbOut;  
	  
	    } // end of HorizontalFiltering()  
	  
	    private static int verticalFilter(BufferedImage pbInImage, int startY, int stopY,  
	            int start, int stop, int x, double[] pContrib) {  
	        double valueRed = 0.0;  
	        double valueGreen = 0.0;  
	        double valueBlue = 0.0;  
	        int valueRGB = 0;  
	        int i, j;  
	  
	        for (i = startY, j = start; i <= stopY; i++, j++) {  
	            valueRGB = pbInImage.getRGB(x, i);  
	  
	            valueRed += GetRedValue(valueRGB) * pContrib[j];  
	            valueGreen += GetGreenValue(valueRGB) * pContrib[j];  
	            valueBlue += GetBlueValue(valueRGB) * pContrib[j];  
	            // System.out.println(valueRed+"->"+Clip((int)valueRed)+"<-");  
	            //  
	            // System.out.println(valueGreen+"->"+Clip((int)valueGreen)+"<-");  
	            // System.out.println(valueBlue+"->"+Clip((int)valueBlue)+"<-"+"-->");  
	        }  
	  
	        valueRGB = ComRGB(clip((int) valueRed), clip((int) valueGreen),  
	                clip((int) valueBlue));  
	        // System.out.println(valueRGB);  
	        return valueRGB;  
	  
	    } // end of VerticalFilter()  
	  
	    private static BufferedImage verticalFiltering(BufferedImage pbImage, int iOutH) {  
	        int iW = pbImage.getWidth();  
	        int iH = pbImage.getHeight();  
	        int value = 0;  
	        BufferedImage pbOut = new BufferedImage(iW, iOutH,  
	                BufferedImage.TYPE_INT_RGB);  
	  
	        for (int y = 0; y < iOutH; y++) {  
	  
	            int startY;  
	            int start;  
	            int Y = (int) (((double) y) * ((double) iH) / ((double) iOutH) + 0.5);  
	  
	            startY = Y - nHalfDots;  
	            if (startY < 0) {  
	                startY = 0;  
	                start = nHalfDots - Y;  
	            } else {  
	                start = 0;  
	            }  
	  
	            int stop;  
	            int stopY = Y + nHalfDots;  
	            if (stopY > (int) (iH - 1)) {  
	                stopY = iH - 1;  
	                stop = nHalfDots + (iH - 1 - Y);  
	            } else {  
	                stop = nHalfDots * 2;  
	            }  
	  
	            if (start > 0 || stop < nDots - 1) {  
	                CalTempContrib(start, stop);  
	                for (int x = 0; x < iW; x++) {  
	                    value = verticalFilter(pbImage, startY, stopY, start, stop,  
	                            x, tmpContrib);  
	                    pbOut.setRGB(x, y, value);  
	                }  
	            } else {  
	                for (int x = 0; x < iW; x++) {  
	                    value = verticalFilter(pbImage, startY, stopY, start, stop,  
	                            x, normContrib);  
	                    pbOut.setRGB(x, y, value);  
	                }  
	            }  
	  
	        }  
	  
	        return pbOut;  
	  
	    } // end of VerticalFiltering()  
	  
	    static  int  clip(int x) {  
	        if (x < 0)  
	            return 0;  
	        if (x > 255)  
	            return 255;  
	        return x;  
	    }  
	    
	    
	    public static BufferedImage toBufferedImage(Image image){
	        if (image instanceof BufferedImage) {  
	            return (BufferedImage)image;  
	        }  
	      
	        // This code ensures that all the pixels in the image are loaded  
	        image = new ImageIcon(image).getImage();  
	      
	        // Determine if the image has transparent pixels; for this method's  
	        // implementation, see e661 Determining If an Image Has Transparent Pixels  
	        boolean hasAlpha = hasAlpha(image);  
	      
	        // Create a buffered image with a format that's compatible with the screen  
	        BufferedImage bimage = null;  
	        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();  
	        try {  
	            // Determine the type of transparency of the new buffered image  
	            int transparency = Transparency.OPAQUE;  
	            if (hasAlpha) {  
	                transparency = Transparency.BITMASK;  
	            }  
	      
	            // Create the buffered image  
	            GraphicsDevice gs = ge.getDefaultScreenDevice();  
	            GraphicsConfiguration gc = gs.getDefaultConfiguration();  
	            bimage = gc.createCompatibleImage(  
	                image.getWidth(null), image.getHeight(null), transparency);  
	        } catch (HeadlessException e) {  
	            // The system does not have a screen  
	        }  
	      
	        if (bimage == null) {  
	            // Create a buffered image using the default color model  
	            int type = BufferedImage.TYPE_INT_RGB;  
	            if (hasAlpha) {  
	                type = BufferedImage.TYPE_INT_ARGB;  
	            }  
	            bimage = new BufferedImage(image.getWidth(null), image.getHeight(null), type);  
	        }  
	      
	        // Copy image to buffered image  
	        Graphics g = bimage.createGraphics();  
	      
	        // Paint the image onto the buffered image  
	        g.drawImage(image, 0, 0, null);  
	        g.dispose();  
	      
	        return bimage;  
	    }  
	    
	    
	    public static boolean hasAlpha(Image image) {  
	        // If buffered image, the color model is readily available  
	        if (image instanceof BufferedImage) {  
	            BufferedImage bimage = (BufferedImage)image;  
	            return bimage.getColorModel().hasAlpha();  
	        }  
	      
	        // Use a pixel grabber to retrieve the image's color model;  
	        // grabbing a single pixel is usually sufficient  
	         PixelGrabber pg = new PixelGrabber(image, 0, 0, 1, 1, false);  
	        try {  
	            pg.grabPixels();  
	        } catch (InterruptedException e) {  
	        }  
	      
	        // Get the image's color model  
	        ColorModel cm = pg.getColorModel();  
	        return cm.hasAlpha();  
	    } 
}
